function maximize1() {
  	document.getElementById('links').style.display = "block";
	document.getElementById('rechts').style.display = "none";
	document.getElementById('mitte').style.display = "block";
}

function hideIdIfIdExists( hideId, existId){
	if( document.getElementById(existId) != undefined ){
		document.getElementById(hideId).style.display = "none";
	}
}